JP2006044438A - Power unit for motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power unit for a motorcycle capable of enabling oil to smoothly flow between a crank case and an oil tank even when the power unit is oscillated. <P>SOLUTION: A rear wheel supporting part is integrated with the power unit, and an oil tank is integrated with a rear part of a crank case. The entire power unit is a unit swing type power unit to be mounted on a motorcycle body frame so as to be vertically oscillated together with the rear wheel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a motorcycle power unit equipped with a dry sump type lubricating device.

  In a conventional motorcycle equipped with a power unit having a dry sump type lubrication device, the power unit is fixed to the body frame, and an oil tank formed separately from the power unit is located at an upper position away from the internal combustion engine. Two hoses for oil supply and oil return are provided between the power unit and the oil tank, which are fixed to the vehicle body frame (see, for example, Patent Document 1).

Japanese Patent No. 3470355 (FIG. 1).

  In the conventional oil tank arrangement, both the power unit and the oil tank are fixed to the body frame, so the mutual positional relationship between the power unit and the oil tank is unchanged, and the oil hose is affected by the swinging of the rear wheels. There was no. However, in the case of a unit swing type power unit in which the power unit and the rear wheel swing together, if the oil tank separate from the power unit is fixed to the vehicle body frame at a position away from the internal combustion engine, the power unit and the oil tank The oil hose between the two is affected by the swinging of the rear wheels. Conventionally, it has been necessary to provide the above-described reciprocating oil pipe between the internal combustion engine and the oil tank, so that the configuration is complicated. In order to improve these, a new oil tank arrangement and its structure have been required.

  The present invention solves the above problems, and the invention according to claim 1 is an internal combustion engine having a crankcase and a cylinder, and an oil for storing oil for lubricating the crankcase and members in the cylinder. In a motorcycle power unit having a tank, the oil tank is a unit swing type power unit that is integrally provided at the rear of the crankcase, and is attached to a vehicle body frame so that the power unit can swing up and down together with a rear wheel. The present invention relates to a motorcycle power unit.

  According to a second aspect of the present invention, in the motorcycle power unit according to the first aspect, a first oil passage communicating from the crankcase to the oil tank is disposed in the crankcase. Is.

  According to a third aspect of the present invention, in the motorcycle power unit according to the second aspect, the first oil passage is provided below a crankshaft disposed in the crankcase, and the oil tank supplies oil from the oil tank. The second oil passage communicating with the pump and the oil filter overlaps with the first oil passage in a side view of the vehicle body and is arranged in parallel with the first oil passage.

  According to a fourth aspect of the present invention, in the motorcycle power unit according to the third aspect, the third oil passage communicating from the oil filter into the crankcase and the cylinder includes the first oil passage and the first oil passage. The second oil passage overlaps with the vehicle body in a side view and is arranged in parallel with the first oil passage.

  According to a fifth aspect of the present invention, in the motorcycle power unit according to the fourth aspect, a scavenging pump for pumping oil in the crankcase to the oil tank, and oil in the oil tank for the crankcase and A feed pump for pumping to each part in the cylinder is coaxially disposed, and these pumps are disposed between the oil filter and the oil tank below the crankshaft. To do.

  According to a sixth aspect of the present invention, in the motorcycle power unit according to the second or fourth aspect, the diameter of the first oil passage is increased toward the rear of the vehicle body, and the third oil passage is disposed at the rear of the vehicle body. It is characterized by being reduced in diameter as it goes to.

  According to a seventh aspect of the present invention, in the motorcycle power unit according to the first aspect, the oil tank is disposed on the opposite side of the cylinder with the crankcase interposed therebetween.

  According to an eighth aspect of the present invention, in the motorcycle power unit according to the first aspect, the unit swing type power unit includes a transmission case that extends rearward from the side of the crankcase, and the vertical direction of the oil tank. The dimension is smaller than the vertical dimension of the transmission case.

  In the invention of claim 1, the oil tank is integrally provided at the rear of the crankcase, and the power unit is attached to the vehicle body frame so that it can swing up and down together with the rear wheel. Oil can flow smoothly between the crankcase and the oil tank.

  In the invention of claim 2, since the oil passage is provided in the crankcase, it is not necessary to provide an oil hose outside the power unit.

  According to the invention of claim 3, the center of gravity can be lowered and the minimum ground clearance can be secured. Also, the space can be used effectively.

  According to the invention of claim 4, the center of gravity can be further lowered and the minimum ground clearance can be secured. Furthermore, the space can be used effectively.

  According to the fifth aspect of the present invention, the oil pump can be arranged more compactly than that arranged on another shaft, and the oil passage can be shortened, so that the piping system can be arranged compactly. Furthermore, since the oil pump is disposed at a position lower than the crankshaft, the center of gravity can be lowered.

  According to the sixth aspect of the present invention, the large-diameter portion and the small-diameter portion of the adjacent pipes can be arranged adjacent to each other, so that the space utilization efficiency is increased and an increase in size can be avoided.

  According to the seventh aspect of the present invention, the oil tank is not easily affected by the heat from the cylinder, so that an increase in the oil temperature can be avoided.

  According to the eighth aspect of the invention, the height of the oil tank can be suppressed, and a decrease in the minimum ground clearance can be avoided.

  FIG. 1 is a view of a longitudinal section of a motorcycle power unit 1 provided with a dry sump type lubricating device according to an embodiment of the present invention, as viewed from the right side. Arrow F points forward. In the power unit 1, an internal combustion engine 2 and a transmission 3 are integrated. The internal combustion engine 2 is an overhead valve type 4-stroke cycle single cylinder water-cooled internal combustion engine. The transmission 3 includes a V-belt continuously variable transmission 4, a gear reducer 5, and a transmission case 6. The transmission case 6 also serves as a rear wheel support portion, and supports a rear wheel (not shown) connected to the gear reducer 5. A pivot shaft insertion hole 6a for attaching the power unit 1 to the vehicle body frame is provided in the upper part of the transmission case 6, and the power unit 1 is attached to the vehicle body frame so as to be vertically swingable through the inserted pivot shaft.

  The internal combustion engine 2 comprises a portion surrounded by a crankcase 7, a cylinder block 8, a cylinder head 9, and a cylinder head cover 10, and a cylinder block 8 oriented in a substantially horizontal direction is coupled to the front surface of the crankcase 7. A cylinder head 9 is coupled to the front end of the cylinder block 8, and a cylinder head cover 10 is coupled to the front end of the cylinder head 9. The crankcase 7 is composed of left and right crankcase portions.

  A crankshaft 12 is rotatably supported by bearings provided on the left and right crankcase portions. A piston 13 is slidably fitted in a cylinder hole 11 formed in the cylinder block 8. Both ends of the connecting rod 16 are pivotally attached to the crankshaft 12 and the piston 13 via the crankpin 14 and the piston pin 15, respectively. When the piston 13 reciprocates, the crankshaft 12 is moved in the crank chamber 17. Driven by rotation.

  The drive shaft of the V-belt type continuously variable transmission 4 is the crankshaft 12 itself, and the drive pulley 20 of the V-belt type continuously variable transmission 4 is provided thereon. The driven shaft 21 of the V-belt type continuously variable transmission 4 is rotatably supported by the transmission case 6, and the driven shaft 21 is connected to the V-belt type continuously variable transmission 4 via a centrifugal clutch (not shown). A driven pulley 22 is provided. An endless V-belt 23 is stretched between the driving pulley 20 and the driven pulley 22.

  The gear reducer 5 includes three rotating shafts and gears provided on these shafts. The first shaft is the driven shaft 21 itself of the V-belt type continuously variable transmission 4, and a driven shaft pinion 25 is formed. The second shaft is an intermediate shaft 26, and an intermediate shaft gear 27 that meshes with the driven shaft pinion 25 is integrally fitted thereto, and an intermediate shaft pinion 28 is formed adjacent thereto. The third shaft is a rear axle 29, and a rear axle gear 30 that meshes with the intermediate shaft pinion 28 is fitted thereto. With this configuration, the torque of the driven shaft 21 is transmitted to the rear axle 29 via the driven shaft pinion 25, the intermediate shaft gear 27, the intermediate shaft 26, the intermediate shaft pinion 28, and the rear axle gear 30, so that the rear axle 29 Is greatly decelerated with respect to the driven shaft 21. A rear wheel is integrally coupled to the rear axle 29.

  A combustion chamber 33 is formed on the bottom surface of the cylinder head 9 facing the front end of the cylinder hole 11, an intake port 34 connected to the combustion chamber 33 is formed on the upper portion of the cylinder head 9, and a combustion chamber is formed on the lower portion of the cylinder head 9. An exhaust port 35 continuing to 33 is formed. An intake valve 36 for opening and closing the opening on the combustion chamber 33 side of the intake port 34 and an exhaust valve 37 for opening and closing the opening on the combustion chamber 33 side of the exhaust port 35 are slidably fitted to the cylinder head 9. .

  The downstream end of the intake pipe 38 is connected to the outer opening of the intake port 34. An air cleaner (not shown), a throttle valve 39, and a fuel injection valve 40 are connected to the intake pipe 38 in order from the upstream side. An upstream end of an exhaust pipe (not shown) is connected to the outer opening of the exhaust port 35, and a downstream end of the exhaust pipe is connected to a muffler (not shown). Furthermore, the intake valve 36 and the exhaust valve 37 urged in the valve closing direction by a valve spring are valve operating devices (in a valve operating chamber 41 formed by the cylinder head 9 and the cylinder head cover 10). (Not shown) is driven to open and close.

  An oil pan 44 is connected to the lower portion of the crank chamber 17. The crank chamber 17 and the oil pan 44 are a continuous space. An oil pump 45 is provided in the vicinity of the boundary between the crank chamber 17 and the oil pan 44. The oil pump 45 includes a coaxial scavenging pump 46 and a feed pump 47, and is connected to the same oil pump shaft 48. A scavenging pump 46 is provided on the right side (front side in FIG. 1). An oil suction port 49 of the scavenging pump 46 is provided adjacent to the lower side of the scavenging pump 46, and the oil flowing down from the crank chamber 17 to the oil pan 44 is sucked up from the oil suction port 49 to the scavenging pump 46. . An oil filter 50 is provided on the front surface of the crankcase 7 and below the cylinder block 8. The crankcase 7 is integrally formed with an oil tank 51 adjacent to the crank chamber 17 and a rear portion of the crank chamber 17. Further, an oil inflow passage 52 is integrally formed along the rear wall of the oil tank 51. Since the oil tank 51 is provided in the power unit disposed below the storage box 53, the capacity of the storage box 53 can be increased.

  FIG. 2 is a developed sectional view taken along the line II-II in FIG. 1, and particularly the vicinity of the oil pump 45 and the oil filter 50 shows the shape when the power unit 1 is viewed from the front. Arrow R points to the right side of the power unit 1 and arrow L points to the left side. This figure mainly shows the inside of the crank chamber 17 and the oil pan 44. A crankshaft 12 oriented in the left-right direction is provided at the center of the crank chamber 17, and is supported by left and right journal bearings 55A, 55B provided in the left and right crankcases 7A, 7B. A generator 56 is provided on the right side of the crank chamber 17, its rotor 57 is connected to the crankshaft 12, and its stator 58 is fixed to a lid 59 of the generator chamber connected to the crankcase 7. A starter motor 60 is provided in the upper part of the crank chamber 17 so that the crankshaft 12 and the generator 56 are rotationally driven via a gear group 61 when the internal combustion engine is started.

  A scavenging pump 46 and a feed pump 47 are connected to a common oil pump shaft 48 at the boundary between the crank chamber 17 and the oil pan 44. An oil pump drive sprocket 63 is provided on the crankshaft 12, an oil pump driven sprocket 64 is provided on the oil pump shaft 48, and an endless chain 65 wound around both the sprockets interlocks with the rotation of the crankshaft 12. The oil pump 45 is driven to rotate. Inside the oil pan 44, an oil suction port 49 of a scavenging pump is provided. Oil is sucked from the lower surface of the oil suction port 49 and sent to the scavenging pump 46 through an oil passage (not shown). In the figure, the destination of the oil from the oil pan 44 to the scavenging pump 46 is indicated by a broken line with an arrow.

  In this figure, the oil filter 50 is indicated by a one-dot chain line. In a front view of the vicinity of the oil pump 45, cross sections of three oil passages 71, 72, 73 are shown between the oil pump 45 and the oil filter 50. The central passage is the first oil passage 71 from the scavenging pump 46 to the oil tank 51, the left passage in the figure is the second oil passage 72 from the oil tank 51 to the feed pump 47, and the right passage in the figure is the oil filter 50. Is a third oil passage 73 for supplying oil from the center to the rear of the crank chamber 17 toward the journal bearings 55A and 55B. There is an oil passage in the left-right direction above the three oil passages. This is a communication passage 74 for sending oil from the feed pump 47 to the oil filter 50. A relief valve 75 is provided below the three oil passages. When the hydraulic pressure of the discharge system of the feed pump 47 rises above a set value, it is a device that discharges the feed oil of the feed pump 47 directly to the oil pan 44 without sending it to the oil filter 50.

  FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, and is a view of the horizontal cross section including the three parallel oil passages 71, 72, 73 as viewed from above. In the figure, an oil inflow port 71a connected to the discharge port of the scavenging pump 46 is provided at the front end portion of the first oil passage 71, and the oil tank 51 (FIG. 1) is directed at the rear end portion of the first oil passage 71. An oil outlet 71b is provided. The rear end of the first oil passage 71 is closed with a fixing plug 71c. An oil inlet 72a connected to the oil tank 51 is provided at the rear end of the second oil passage 72, and an oil outlet 72b toward the suction port of the feed pump 47 is provided at the front end of the second oil passage 72. . The rear end of the second oil passage 72 is closed with a fixing plug 72c. The front end of the third oil passage 73 is connected to the center of the rear surface of the oil filter 50. A rising passage 80 directed upward is provided at the rear end of the third oil passage 73, and a lateral communication passage 81 directed in the left-right direction for supplying oil to the journal bearings 55A and 55B is connected to the upper end thereof. A pair of communication ports 82 for supplying oil to the left and right journal bearings 55A and 55B are provided at both ends of the lateral communication passage 81. In the figure, the oil flow is indicated by broken lines with arrows.

  The three oil passages 71, 72, 73 are integrally manufactured by casting. Although not shown in this drawing, the three oil passages 71, 72, 73 are also manufactured integrally with the left crankcase 7A. The first and third oil passages 71 and 73 have opposite taper directions, and share the pipe wall of the adjacent portion for effective use of space. The taper of the three oil passages 71, 72, 73 is cast using a tapered core.

  FIG. 4 is a view of a longitudinal section of the internal combustion engine 2 including the first oil passage 71 as seen from the right side. Oil that has flowed down from the crank chamber 17 to the oil pan 44 during operation of the internal combustion engine is sucked into the scavenging pump 46 from the oil suction port 49 of the scavenging pump 46. By the rotation of the scavenging pump 46, oil is discharged from the discharge port of the pump 46 to the oil inlet 71a of the first oil passage 71, passes through the first oil passage 71 to the rear end, and the oil flow at the rear end portion. The oil is injected into the oil tank 51 from the upper part through the oil inflow passage 52 on the rear wall of the oil tank 51 from the outlet 71b and stored in the oil tank 51. The reason for injecting oil into the oil tank 51 from the top is to prevent the oil in the oil tank 51 from flowing back into the first oil passage 71. The screw plug 84 below the rear end of the first oil passage 71 is for closing the opening used for drilling the oil outlet 71b.

  FIG. 5 is a view of a longitudinal section of the internal combustion engine 2 including the second oil passage 72 as seen from the right side. The oil stored in the oil tank 51 flows out from the lower part of the oil tank 51 to the oil inlet 72a of the second oil passage 72, and passes through the second oil passage 72 to the feed pump 47 from the oil outlet 72b at the front end thereof. Inhaled. The oil discharged from the feed pump 47 is sent to the oil filter 50 via the communication passage 74 (see also FIG. 2). The relief valve 75 is provided in communication with the inflow portion of the oil filter 50. When pressure equal to or higher than the set value is generated in the feed pump discharge system, the oil is discharged from the relief valve 75 to the oil pan 44.

  FIG. 6 is a view of a longitudinal section of the internal combustion engine 2 including the third oil passage 73 as viewed from the right. The front end of the third oil passage 73 is connected to the oil filter 50. A rising passage 80 (see also FIG. 3) is connected to the rear end portion of the third oil passage 73 upward. A lateral communication passage 81 (see also FIG. 3) facing the left and right direction is connected to the upper end of the rising passage 80, and obliquely upward along the left and right crankcases 7A and 7B from both ends of the lateral communication passage 81, respectively. A pair of left and right oil supply passages 83A and 83B are provided. This is an oil passage toward the left and right journal bearings 55A and 55B. The oil sent from the feed pump 47 and passed through the oil filter 50 flows out from the center of the rear surface of the oil filter 50 to the third oil passage 73, passes through the third oil passage 73 and reaches the rear portion of the oil passage 73. Through the ascending passage 80, the lateral communication passage 81 and the communication port 82, the left and right journal bearings 55A and 55B (FIG. 2) are supplied through the left and right oil supply passages 83A and 83B. The screw plug 85 attached to the lower end of the rear end of the third oil passage 73 closes the opening used when the ascending passage 80 is drilled. Screw plugs 86 attached to the lower ends of the left and right oil supply passages 83A and 83B close the opening used when the communication port 82 is drilled.

  A part of the oil supplied to the journal bearings 55A and 55B and lubricating the bearing portion flows out from the opening 91 of the crank pin 14 via the oil passage 90 in the crankshaft shown in FIG. 2, and the large size of the connecting rod 16 shown in FIG. Lubricate the roller bearing 92 on the inner surface of the end. Although not shown, oil injection holes and oil passages along the cylinder wall are provided, so that oil is sent to the cylinder inner surface, valve mechanism, piston pin, etc., and lubricates each part. It has become.

As described above in detail, the following effects are brought about in this embodiment.
(1) The oil tank is provided integrally behind the crankcase, and the power unit is mounted on the vehicle body frame so that it can swing up and down with the rear wheels. It can flow smoothly between oil tanks.
(2) Since the oil passage is provided in the crankcase, it is not necessary to provide an oil hose outside the power unit.
(3) Since the oil passage is provided below the crankshaft and the second oil passage is disposed in parallel to the first oil passage, the center of gravity can be lowered and the minimum ground clearance can be secured. it can. Also, the space can be used effectively.
(4) Since the third oil passage is also arranged in parallel with the first and second oil passages, the center of gravity can be further lowered and the minimum ground clearance can be secured. Furthermore, the space can be used effectively.
(5) Since the scavenging pump 46 and the feed pump 47 are coaxially arranged, the oil pump can be arranged more compactly than the one arranged on another shaft, the oil passage can be shortened, and the piping system can be arranged compactly. I can do it. Furthermore, since the oil pump is disposed at a position lower than the crankshaft, the center of gravity can be lowered.
(6) Since the large-diameter portion and the small-diameter portion of the adjacent pipes are adjacent to each other, the space utilization efficiency is increased and a configuration that avoids an increase in size can be achieved.
(7) Since the oil tank is provided on the opposite side of the cylinder across the crankcase, the oil tank is less susceptible to the heat from the cylinder, and an increase in oil temperature can be avoided.
(8) Since the vertical height of the oil tank 51 is lower than the vertical height of the transmission case 6, it is possible to suppress the height of the oil tank and to avoid a decrease in the minimum ground clearance.
(9) Since the crankcase and the oil tank are integrally formed, and the oil passage connecting the crankcase and the oil tank is also integrally formed with the crankcase and the oil tank, the number of parts can be reduced.
(10) The oil inflow passage 52 from the first oil passage to the oil tank extends upward along the rear wall surface of the oil tank 51 and opens at the upper portion of the oil tank. As a result, even if the oil level rises, the oil is prevented from flowing back to the first oil passage, and the capacity of the oil tank can be increased.
(11) Since the pipe wall of the first oil passage 71 and the pipe wall of the third oil passage 73 are shared, the arrangement of the pipes is compact.
(12) Since the oil tank 51 is provided in the power unit disposed below the storage box 53, the capacity of the storage box 53 can be increased.

It is the figure which looked at the longitudinal section of power unit 1 for motorcycles from the right. FIG. 2 is a developed sectional view taken along the line II-II in FIG. 1. It is III-III sectional drawing of FIG. FIG. 2 is a view of a longitudinal section of an internal combustion engine 2 including a first oil passage 71 as viewed from the right. FIG. 3 is a view of a longitudinal section of an internal combustion engine 2 including a second oil passage 72 as viewed from the right. FIG. 6 is a view of a longitudinal section of the internal combustion engine 2 including a third oil passage 73 as viewed from the right.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power unit, 2 ... Internal combustion engine, 3 ... Transmission, 6 ... Transmission case, 6a ... Pivot shaft insertion hole, 7 ... Crank case, 8 ... Cylinder block, 9 ... Cylinder head, 10 ... Cylinder head cover, 12 ... Crank Shaft, 13 ... piston, 17 ... Crank chamber, 44 ... oil pan, 45 ... oil pump, 46 ... scavenging pump, 47 ... feed pump, 48 ... oil pump shaft, 49 ... oil inlet, 50 ... oil filter, 51 ... oil tank, 52 ... oil inflow passage, 53 ... storage box, 71 ... first oil passage, 72 ... second oil passage, 73 ... third oil passage, 80 ... ascending passage, 81 ... lateral communication passage, 82 ... Communication port (a pair of left and right), 83A, 83B ... left and right oil supply passages.

Claims (8)

An internal combustion engine having a crankcase and a cylinder;
In a motorcycle power unit comprising an oil tank for storing oil for lubricating the crankcase and the member in the cylinder,
The oil tank is integrally provided behind the crankcase,
A power unit for a motorcycle, wherein the power unit is a unit swing type power unit attached to a vehicle body frame so as to swing up and down together with a rear wheel. 2. The motorcycle power unit according to claim 1, wherein a first oil passage communicating from the crankcase to the oil tank is disposed in the crankcase. The first oil passage is provided below a crankshaft disposed in the crankcase;
The second oil passage communicating from the oil tank to the oil pump and the oil filter overlaps with the first oil passage in a side view of the vehicle body, and is arranged in parallel with the first oil passage. The motorcycle power unit according to claim 2. A third oil passage communicating from the oil filter into the crankcase and the cylinder overlaps the first oil passage and the second oil passage in a side view of the vehicle body,
4. The motorcycle power unit according to claim 3, wherein the motorcycle power unit is arranged in parallel with the first oil passage. A scavenging pump for pumping oil in the crankcase to the oil tank and a feed pump for pumping oil in the oil tank to the crankcase and each part in the cylinder are arranged coaxially. ,
The motorcycle power unit according to claim 4, wherein these pumps are disposed below the crankshaft and between the oil filter and the oil tank. The motorcycle according to claim 2 or 4, wherein the diameter of the first oil passage increases toward the rear of the vehicle body, and the diameter of the third oil passage decreases toward the rear of the vehicle body. Power unit. 2. The motorcycle power unit according to claim 1, wherein the oil tank is disposed on the opposite side of the cylinder with the crankcase interposed therebetween. The unit swing type power unit includes a transmission case extending rearward from the side of the crankcase,
2. The motorcycle power unit according to claim 1, wherein a vertical dimension of the oil tank is smaller than a vertical dimension of the transmission case. 3.

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